1. Field of the Invention
The present invention relates to a method for controlling a pausing period of a defrosting operation for minimizing a temperature deviation in a refrigerator through the optimum variation of the pausing period of the defrosting operation based on the present temperature in the refrigerator and the present pressure of the discharging outlet of a compressor.
2. Description of the Prior Art
Generally, a refrigerator includes a heater for a defrosting operation for removing frost formed around an evaporator. When the accumulated operating time of a compressor is a first predetermined time (for example, 8 hours) or over, a controlling apparatus for the refrigerator selects a defrosting mode without any condition and carries out the defrosting operation. In addition when the accumulated operating time of the compressor is a second predetermined time (for example, 5 hours) or over, the controlling apparatus for the refrigerator reads the accumulated time for a door opening, the operating ratio of the compressor, etc. and carries out the defrosting operation.
When the defrosting mode is selected, the controlling apparatus for the refrigerator operates the heater for the defrosting operation and detects the temperature around the evaporator through a defrosting sensor. When the detected temperature is a predetermined restoring temperature for the defrosting operation (for example, 13.degree. C.) or over, the operation of the heater for the defrosting operation (i.e. a heat generating operation) is stopped. Meanwhile when the detected temperature is the restoring temperature for the defrosting operation or below, the heater for the defrosting operation is operated for a predetermined time (for example, for 90 minutes) and then the operation thereof is stopped.
After the operation of the refrigerator at the defrosting mode as described above, the temperature in the refrigerator is usually -10.degree. C. or over. If the refrigerator is commonly operated, the temperature in the refrigerator is about -16.degree. C..about.-20.degree. C. After the defrosting operation and during the pausing period of the defrosting operation, which is fixed as a predetermined time interval (for example, 4.about.7 minutes), the temperature in the refrigerator can be further increased.
In order to lower the increased temperature in the refrigerator to the temperature in the refrigerator during the common operation, the operating time of the compressor should be increased. This will increase the consuming power of the refrigerator. In addition, the temperature in the refrigerator at the common operating mode of the refrigerator is different from the temperature in the refrigerator at the defrosting mode. Therefore, it is difficult for food stored in the refrigerator to keep in an optimally fresh state.
Accordingly, the method for controlling the defrosting operation as described above fixes the pausing period of the defrosting operation irrespective of the temperature in the refrigerator after the defrosting operation and induces the increase in the temperature of the refrigerator.
A method for automatically controlling the operation of the refrigerator is disclosed in U.S. Pat. No. 5,228,300 (granted to Shim). In this patent, the operations of the compressor and a fan motor are delayed after the completion of a defrosting cycling for minimizing the increase of the temperature in the refrigerator. And in the controlling method, the temperature setting of a chamber, the defrost cycling and the operation of a compressor and a fan motor are automatically controlled according to the the door open/close frequency and open time. According to the present state of a temperature adjusting apparatus and the mean temperature of the refrigerator, the temperature in the refrigerator is lowered and the defrosting cycling is operated for a predetermined time interval or an auxiliary time interval according to the utilization number of the refrigerator and the opening time of the door before the defrosting cycle. The operations of the compressor and the fan motor are delayed so that the temperature in the refrigerator is not increased after the completion of the defrosting cycling to minimize the temperature variation in the refrigerator and to protect the stored food.
However, after the defrosting operation, the method for controlling the defrosting operation as described above could not actively cope with the increase in the temperature in the refrigerator and with the increase in the consuming power of the refrigerator. Therefore, the pausing period of the defrosting operation could not be optimally varied.